Hyperpigmentation is a common skin condition in which flat, dark spots and patches appear on the face, hands and other parts of the body that are regularly exposed to the sun.
Our natural eye, hair and skin colour, is determined by the amount and type of melanin pigment that our cells produce. Melanin is produced by specialised cells called melanocytes in the basal layer of the epidermis, and transferred to the upper layers of the skin in the keratinocyte cells, where they provide protection to the cell’s nucleus.
Interestingly, everyone has the same number of melanocyte cells, but those in the skin of people with darker tones produce pigment more efficiently and have more of the brown-black eumelanin than those with paler skin who have more yellow-red pheomelanin. As a result of this the pigmented marks can be black, grey, brown, red or pink in colour
Melanin is produced when we are exposed to UltraViolet (UV) light. The pigment provides protection to the cells against damage by the sun, and as a result production will increase with increased exposure. However, over time regulation of the melanocytes can become unstable and they respond to various triggers by producing excessive amounts of melanin. Distribution of the pigment can also be affected, with melanin being produced in concentrated spots, the result being that the skin tone appears patchy and uneven.
What causes Hyperpigmentation?
There are a number of different factors that can influence the development of hyperpigmentation
- UV radiation exposure
- Inflammation
- Hormonal fluctuations
- Age
- Medication
UV radiation exposure and inflammation are the two major triggers for hyperpigmentation. But more than one factor can affect the melanocyte at the same time, often increasing and intensifying the effects of others.
UV radiation exposure
When unprotected skin is exposed to UV radiation (from the sun or sun beds) it causes a chemical called Tyrosinase to be released and this kick-starts a process in the skin that results in the release of melanin. Melanin acts as a natural sunscreen which is why people tan in response to UV exposure. Unfortunately constant or excessive sun exposure can disrupt melanin production, leading to hyperpigmentation.
Once dark spots have developed, further exposure or the effect of one of the other factors can exacerbate the issue by making the marks even darker.
Inflammation
Tyrosinase is similarly released as part of the chain reaction when the melanocyte is damaged as a result of inflammation. One of the main causes of inflammatory related hyperpigmentation (known as post-inflammatory hyperpigmentation or PIH) is acne, but cuts, burns and many topical medications such as benzoyl peroxide or skincare products that irritate the skin can also prompt the reaction and lead to hyperpigmentation
Hormones
Fluctuations in the female hormones oestrogen and progesterone are thought to influence the production of tyrosinase and stimulate the overproduction of melanin when the skin is exposed to sunlight. This is the main cause of a type of hyperpigmentation called melasma or chloasma. A similar response has also been seen as a side effect of certain hormone treatments.
Age
The number of melanocytes has been shown to decrease by about 10% each decade after the age of 30, leading to their distribution in the skin gradually becoming more clustered. In addition, the remaining cells increase in size, and as a result the release of melanin becomes less uniform. Research suggests that these physical changes explain the increasing appearance of dark spots in exposed skin in those over the age of 40.
Genetics
Hyperpigmentation can have a familial link e.g very light skinned people, particularly those with red hair often have a particular gene that predisposes them to developing freckles.
Diseases and Medications
Certain conditions e.g. Addison’s disease and some thyroid problems can cause the development of hyperpigmentation. Some medications can also make skin ‘light sensitive’ and so increase the potential for hyperpigmentation, examples include oral contraceptives and antibiotics.
Hyperpigmentation is actually an umbrella term used to describe any area of excess pigmentation. But actually there are various types of pigmented lesions with different characteristics, and we more usually refer to them by their unique name which is often related to their main causal factor.
Solar Lentigines – also known as Sun Spots, Age Spots or Liver Spots
As their name suggests these are caused by excessive and/or regular exposure to UV radiation. As sun damage is cumulative solar lentigines often appear after the age of 40, hence the alternative name of ‘age spots’.
Solar lentigines tend to rounded or oval in shape
Post-Inflammatory Hyperpigmentation – PIH
As noted, this occurs following a trauma to the skin (burn, cut or acne breakout), or where it is irritated by topical skin care products or sensitised by oral medications. Whatever the trigger, the resulting inflammation damages the melanocytes causing it to overproduce melanin in response to UV exposure.
The appearance of PIH lesions varies greatly depending on the skin’s natural tone – lighter skins, those defined as Fitzpatrick types I to III, develop pink through to purple marks, while darker skin tones, those defined as Fitzpatrick types IV to VI develop brown through to black and grey, or blue through to purple marks.
The size and shape of PIH marks also vary greatly. Marks on lighter skin tend to correspond to the site of the original blemish or cut, but marks on darker skin tones can be far more diffuse. This is due to the fact that Fitzpatrick types IV to VI tend to have far more reactive melanocytes
Melasma (chloasma)
Melasma appears as brown through to greyish-brown marks, generally on the cheeks, chin, bridge of the nose, forehead, and above the upper lip. As noted, it is related to fluctuations in the female hormones and so is more common in women than men. Pregnancy is a common trigger and so the condition is often referred to as the ‘mask of pregnancy’. It also affects woman taking oral contraceptives and HRT
Ephelides – more commonly known as ‘freckles
People with freckles generally have a genetic predisposition to them, however they often only appear or become more apparent after exposure to UV radiation.
Treating Hyperpigmentation
Note:It’s important to remember that melanocyte cells reside in the lowest level of the epidermis allowing them to disperse pigment up through all of the layers above. In addition, where the cell has been damaged pigment can also ‘leak’ down into the underlying dermis. For this reason, treating hyperpigmentation can require a series of sessions to be successful. The treatment modality will depend on the type and extent of the hyperpigmentation and can vary depending on your unique circumstances.
The First Step:
An initial in-depth consultation and skin health assessment is important to determine the likely causes of the hyperpigmentation and design a treatment and management plan suitable for your unique circumstances.
In Clinic Treatments
The actual treatment options will depend on your unique skin circumstances and the severity of the issues but can include the following
Peels – Either chemical or metabolic. They work by initiating the skin’s natural healing response, which encourages cellular renewal and so prompting exfoliation of the epidermis, gradually lifting away the hyperpigmentation. The choice of peel will depend on your unique skin condition..
Microneedling and mesotherapy– can be extremely effective at breaking down pigmentation marks and helping to regularise pigment production.
Cryotherapy: small localised spots of hyperpigmentation may be suitable for treatment using cold therapy.
Please note it can often be beneficial to combine treatment therapies and bespoke packages attract significant discounts and savings.
Homecare – a suitable homecare regime will be devised for you to follow in between treatments to support the in-clinic therapies. This will be discussed during your initial investigative consultation. It is important to realise that hyperpigmentation can be slow to resolve as pigment generally has to ‘move up’ through the epidermal layers to be removed. In addition, further exposure to the triggering factors without protection will prevent its removal and encourage its return. It is therefore critical to follow the homecare guidance with care, and in particular use a suitable sun protection product daily (minimum SPF50).
